M90 motor and capacitor question.

Status
Not open for further replies.

blu_fuz

Moderator
Staff member
Jun 3, 2009
10,665
153
63
40
WI
So the M90 im working on is missing a 22uf 50v 220uf 16V cap across the terminals of the cassette motor.

First question is why, why would someone cut motor wires and remove that cap?

Second question, is that the correct information for the missing cap?


Thanks!

Here is the motor that im working on.
image.jpg

This is what it should look like.
image.jpg

Here is the schematic:
image.jpg
 

Michiel

Member (SA)
Dec 29, 2012
209
41
28
Netherlands
Your photos shows the capstan motor, but you point to the reel motor on the schematic. The capstan motor needs 220uf, 16V according to the service manual.
 

blu_fuz

Moderator
Staff member
Jun 3, 2009
10,665
153
63
40
WI
Ok. Woops. You are right, this motor drives the big flywheel.
 

blu_fuz

Moderator
Staff member
Jun 3, 2009
10,665
153
63
40
WI
Thank you.

Any idea why someone would take that off?


I dont have that value cap here but i do have a 220uf 10v, is that able to be used or should i buy the one it needs?
 

Michiel

Member (SA)
Dec 29, 2012
209
41
28
Netherlands
Just a theory. :) .. Maybe someone noticed a motor hum and tried to replace the cap. But didn't finish the job. Most likely because the hum wasn't eliminated by the new cap.... Because the hum was caused by a badly earthed shield between the motor and amp board.

Using a higher voltage cap is no problem. Don't use a lower voltage as it might blow. So try to find an other one!
 

Superduper

Member (SA)
You cannot use a 220/10 cap to replace a 22/50 cap. First even if the additional charge time is not an issue, the voltage certainly is. The lower spec cap might literally blow up or expand like popcorn.

Now, that being said, the cap in the picture looks bigger than a 22uf. I bet if you look closely, it's actually a 100 or probably 220uf. If so, you can use a 220/16, 220/25, or anything that is rated at 16v or higher.

Lastly, most BOOMBOX motors don't have that cap. It's possible that it's a replacement motor.
 

blu_fuz

Moderator
Staff member
Jun 3, 2009
10,665
153
63
40
WI
Yes Norm. I was only asking if i could use a 220uf 10v in the position of the 220uf 16v that looks to be missing. I did remember from my panasonic re-cap that i need to keep the uf rating the same, but there was some lee-way for using a cap with a different voltage (couldnt remember if i could go +/- voltage).

I dont have that specific cap in stock, thats why i asked.

If it is a replacement motor, or not, will it be ok to hook this back up with no cap and run it? I had to order the correct cap, i only have 220uf 10v here.
 

Superduper

Member (SA)
I'm sure it will work fine without it but in the long run, it's better for it to be present as it gives the motor a little extra umph to get over those humps like when mechanism is resetting. I'm sure I have it somewhere but I would have to search for my parts stock. Alternatively you can simply get one at your local radio shack. You have those in your very remote part of the country, right? Lol.
 

blu_fuz

Moderator
Staff member
Jun 3, 2009
10,665
153
63
40
WI
I looked through the lasonic pcb i have at home and i didnt find one. My M70 pcbs are all boxed up at work.

I am on baby duty today, so no running to rad shack for me lol.

Ill get the cap in there when it shows up. Other than that, i should be just about ready to put this M90 back together tonight.
 

blu_fuz

Moderator
Staff member
Jun 3, 2009
10,665
153
63
40
WI
I rebelted the deck. Soldered the wires back to it and its still dead. Doesnt click, rotate, hum, nothing.
 

blu_fuz

Moderator
Staff member
Jun 3, 2009
10,665
153
63
40
WI
The deck has never worked since this member bought it. There were unhooked connectors and wires taken off the cassette motor. Maybe the last owner fried it, I have no idea why it was messed with in the first place.
 

blu_fuz

Moderator
Staff member
Jun 3, 2009
10,665
153
63
40
WI
Uhhhh is this M90 missing one of the fusible resistors on this board???


image.jpg
 
Status
Not open for further replies.